Advice on a DIY "LS" Coil Upgrade vs. Sticking w/ Stock
 

Hello everyone,

After much reading on the forums I've found that many elect to preform an "LS" ignition upgrade by putting in better coils as well as some new usually higher gauge spark plug wires. I initially considered preforming this upgrade myself but have found it difficult to find any legitimate coils for sale. I've looked on a variety of the sites AC Delco provides that as authorized resellers but have had no luck finding any D585 AC Delco branded coils and discovered that most of the new AC Delco coils are made in Mexico anyway and don't preform all that well. It would appear the sellers on eBay and Amazon sell either knockoffs or "High Preformance CarBole" branded coils with some pretty impressive specs; However after some more research these don't sound very good from a reliability standpoint and the technical specifications are all over the place as far as the winding ratio and max current/voltage. Also they are typically only sold in packs of 8. I know there's the BHR kit that includes a bracket but that is out of the question as far as price. Ultimately I am trying to decide whether to try to find the new high performance coil that is readily available and compatible or to just buy some standard replacement coils and skip the "upgrade" opportunity.

Does anyone have any thoughts on increased engine performance or stability after this upgrade or have any suggestions as to which coils to buy? Do the legitimate LS coils really last so much longer they are worth the effort?

As always thanks for reading and any input is appreciated.

There's no increase in performance if your existing coils were working fine to begin with. Long term reliability should be better but even good coils can fail. Nobody has done a proper statistical study on this so all of the evidence is anecdotal. Also, keep in mind that D585 coils don't produce as strong of a spark as OEM coils at stock dwell settings. You need to increase the dwell settings (using a Cobb AP, MazdaEdit, or VersaTuner) to get OEM equivalent spark

All that said, I went with Napa "Echlin" brand coils when the craptacular D585 coils that came with my used kit finally crapped out last month. The old coils had red plastic bodies with black metal mounting sleeve. They looked identical to the ones you see on Amazon sold as part of the various RX-8 LS coil kits.

If you want to look at autoparts stores, set your vehicle to 2006 Silverado 1500 6.0L V8. That's how I found mine.

That's what I was hoping not to hear about those CarBole coils but I figured the price was too good to be true.

So you're Echlin coils didn't require any form of tune?
We're they able to be mounted to the LS bracket from your old kit?

Also, if there's somewhere I can just get some more stock coils for under 80$ and they will get me another 20k miles and buying better coils won't reduce the 8's infamous intermittent rough idle then I'll probably just do that.

No, I had VersaTuner to increase OMP rate and change radiator fan trigger temps. Later, when I upgraded the coils, I increased the dwell time. I left the dwell time alone when I switched from the crap red D585s to the Echlins.

Yes, all D585 coils are externally identical (IIRC, D585 is just the physical form factor) so they should all physically fit just fine.

The only thing I can say about finding coils for less than $80 is to not cheap out on anything RX-8 related. Anything.
A set of Mazda JDM Rev.C coils is $230 from Mazmart. That's as close as you can get to guaranteed quality.

Definitely agree on not wanting to cheap out. From what I understand the butterfly effect on engine failure in RX-8s can often be traced back through the cat to something as simple and bad ignition coils and plugs.

Also is it worth getting new NGK wires?

Yah, you're spot on. Ignition causes misfires. Misfires cause unburnt fuel to damage the cat. Enough of this can cause the cat to break up and clog the exhaust. If that happens, you can get hot spots around the exhaust ports which can damage the coolant seal. Boom, rebuild time.

If your existing wires are in poor shape, yes. You can test them to see if they need replacing.

I appreciate all of your insight, I am just going to order the plugs and wires as there is currently an eBay site-wide sale for 15% off. I guess I'll just wait on the coils until I can find some at an authorized retailer for a good price. I saw some Mazda dealer's online site selling the type C coil set for $210.

Just remember eBay and Amazon are the dumping grounds for all sorts of counterfeits, knock-offs, and otherwise crazy shit.
Mazmart, Mazdatrix, Racing Beat, RX8Performance... These are the places that you can trust.

Amen to that

I know Mazdatrix has an eBay storefront so maybe you can leverage off of that.

Remember to check if the ignition coils are the Revision C type.

Thanks for letting me know, if eBay runs another 15-20% code I'll probably just order from that.